This document provides recommendations for modifications to the current TMDD standard. Its goal is to provide a foundation for modernizing the standard. This document specifically provides recommendations for implementing this project’s gap analysis recommendations related to providing security guidance for each approved transmission protocol. Included in this document are recommendations related to a new volume of the specification dealing with minimum security requirements and security recommendations for each data transmission protocol.

This document provides a set of recommendations for modernization of the Traffic Management Data Dictionary (TMDD) (1), currently at version 3.1. These recommendations are based upon the following: Connected Corridors project experience; three previous technical memorandums provided under this project discussing the current and future state of transportation, the state of the supporting technology for information exchange, and a review of the TMDD standard; a gap analysis based on the three technical memorandums delivered as part of this project. The intention of this document is to inform the Institute of Transportation Engineers (ITE) committee responsible for TMDD, the California Department of Transportation (Caltrans), and users of the standard of potential improvements in the standard that should improve its ability to serve current and future transportation and traffic management needs

This document provides a guide to the reference sample application developed under the Traffic Management Data Dictionary (TMDD) modernization contract. The application provides a sample implementation of a SOAP implementation using the XML Schema Definition (XSD) and Web Service Description Language (WSDL) developed under the contract. In addition, it provides a sample implementation of a Kafka/JSON based messaging implementation. Both implementations utilize a sample set of data captured during the I-210 Connected Corridors contract. The application is intended for use by experienced Information Technology (IT) personnel as an example of both SOAP and Kafka implementations of a Center-to-Center (C2C) information exchange system.

Cybersecurity has become a critical issue in today’s world. In the past, security of our cyberspace was an important issue for some sectors of the economy, especially those dealing with financial information, personal identification related information, corporate systems and trade secrets, government classified information, and other types of data considered valuable targets for hackers. For other sectors, there was much less attention and resources dedicated to protection of our information and control systems. These sectors were often considered less likely to be targeted and a less valuable target.

This document presents a review of the Traffic Management Data Dictionary (TMDD) standard, specifically version 3.03d with some analysis of the newest version 3.1, released in January 2020. The intention of this document is to provide a review of this standard for transmission of data between traffic management centers (TMCs), with specific commentary on usability of the standard with specific examples based on its implementation in the Caltrans I-210 Connected Corridors program. TMDD is published by the Institute of Transportation Engineers (ITE), an international organization of transportation engineers and the American Association of State Highway and Transportation Officials (AASHTO), an organization of highway and transportation officials in the United States with members from all 50 states, the District of Columbia, and Puerto Rico. The standard is provided in two parts, along with a reference guide, providing guidance for those developing, procuring, or implementing systems that communicate traffic and transportation device information between or within traffic management centers (TMCs). This includes information regarding system requirements, interface design, communication methods, as well as data schema and definitions.

This document provides a gap analysis based on three previous technical memorandums delivered as part of this project, including a review of the Traffic Management Data Dictionary (TMDD) standard, a review of current and future transportation needs, and a review of the state of the art in technology and systems development. The intention of this document is to provide a review of this standard for transmission of data between traffic management centers (TMCs), with explicit commentary on usability of the standard with specific examples based on its implementation in the Caltrans I-210 Connected Corridors program.

This document presents a review of the current and future requirements for information exchange between traffic management centers, with emphasis on the changes expected due to the changing nature of transportation and the advances in technology that are becoming prevalent in the transportation ecosystem. The intent of this document is to provide a look at the source of changes required within center-to-center communication and new requirements that will need to be addressed as transportation undergoes significant change due to new transportation modes, technology advances in connected and automated vehicles, advances in infrastructure elements, and other changes that are expected in the future.

Abstract: Wilderness visitation, particularly overnight use, is reactive to climate variability because backpackers face greater exposure to and dependence on environmental conditions. This study examines the effect that spring snowpack had on the timing and volume of permits issued for overnight use of the Yosemite Wilderness during peak and shoulder-season months (April–October) from 2002 to 2019. We categorize 1 April snowpack at Tuolumne Meadows into snow drought (<75%), high snowpack (>125%), and near-average snowpack (75%–125%). Results confirm wilderness-wide differences between snowpack categories, including change in spring overnight visitors (April–June: +20% snow drought and −28% high snowpack). Our findings confirm that snow drought allows for more access to high-elevation trailheads when seasonal roads are open earlier in spring (May–June: +74% Tioga Road and +81% Tuolumne Meadows). Mid- to high-elevation trailheads experience a sustained increase in use during high-snowpack years (June–October: +12% Yosemite Valley and Big Oak Flat; +15% Glacier Point Road and Wawona; +32% Hetch Hetchy) because a narrower seasonal access window leads to filled permit quotas in the high country and displaces use to lower-elevation trailheads. These findings have implications for wilderness stewards, including biophysical and experiential impacts on wilderness character from earlier and longer seasons, especially at higher elevation and in fragile alpine and subalpine areas, as snow drought in mountain-protected areas becomes more common. Recommendations to address greater early-season use and its attendant impacts include adaptively managing permits for different types of snowpack years, including potential changes in the number, timing, and destination of select trailhead quotas.